18 LECANO-LECIDEEI [lECIDEA 



indistinct, irregular, slender, dark bluish-black at the apices ; 

 spores oblong, 0,007-10 mm. long, 0,0035-45 mm. thick ; hy- 

 menial gelatine blue then brownish with iodine. — Leight. I. c. 

 Specimen not seen. 



Hah. On rocks. Collected by Dr. Stirton in Island of Mull. 



§ii. BiATORA Fr. in Vet. Ak. Handl. 1882 p. G3 ; Nyl. in 

 Mem. Soc. Cherb. ii. p. 182 (PI. 6). 



Thallus very variable, at times almost obsolete. Apothecia 

 biatorine, plane or convex, brightly coloured, partly or very 

 rarely entirely black ; asci usually 8-spored ; spores simple, 

 colourless. Spermogones with simple rarely jointed sterigmata 

 and straight very rarely arcuate spermatia. 



16. L. cinnabarina Sommerf. in Yet. Ak. Handl. p. 115 (1823). 

 — Thallus effuse, thin, smooth or leprose-granulose, whitish 

 (K+yellowish, CaCl — ). Apothecia adnate or appressed, some- 

 what plane and obtusely margined, then convex and immarginate, 

 cinnabarine-reddish ; paraphyses coherent ; epithecium reddish 

 (K+ rose-coloured) ; hypothecium colourless ; spores oblong or 

 fusiform, small, 0,008-12 mm. long, 0,002-3 mm. thick ; hymenial 

 gelatine, especially the asci, bluish with iodine. — Cromb. in 

 Grevillea xxii. p. 9. 



A very distinct species, readily distinguished by the colour of the 

 apothecia. The thallus, which elsewhere spreads extensively, is 

 sprinkled with whitish, pulvinate soredia. It is one of our rarest 

 lichens, only two fertile British specimens having been gathered, 

 though the sterile thallus may not be uncommon in the district 

 cited. 



Hah. On the smooth bark of old stunted birches in a wooded 

 mountainous region. — jB. M. Mar Forest, Braemar, Aberdeenshire (the 

 only locality). 



17. L. lucida Ach. Meth. p. 74 (1803).— Thallus effuse, thin, 

 leprose, rarely granulose, yellow, citrine-yellow or yellowish-green 

 (K — , CaCl — ). Apothecia minute, scattered, plane or convex, 

 very thinly margined or immarginate, pale lemon-yellow ; spores 

 oblong-ovoid or narrowly obovate, simple, colourless, minute, 

 0,004-6 mm. long, 0,0018-25 mm. thick ; hypothecium colourless ; 

 paraphyses stoutish, coherent ; epithecium granulose ; hymenial 

 gelatine bluish then wine-red with iodine. — S. F. Gray Nat. 

 Arr. i. p. 475 ; Hook. Fl. Scot. ii. p. 40 & in Sm. Engl. Fl. v. 

 p. 185; Mudd Man. p. 193; Cromb. Lich. Brit. p. 65; Leight. 

 Lich. Fl. p. 258 ; ed. 3, p. 254. Lichen lucidns Ach. Prodr. p. 39 

 (1798); Engl. Bot. 1. 1550. 



Exsicc. Leight. n. 385; Larb. Csesar. n. 36, Lich. Hb. n. 306. 



Easily recognized among the allied species by the colour of the 

 thallus and of the apothecia. When sterile, as is very frequently the 

 case in this country', the thallus has a superficial resemblance to that 

 of Coniocyhe furfuracea , for which it might be mistaken. The algal 



